施氮量对冬小麦根系生长分布及产量的影响

在土壤肥力较高的大田条件下,研究氮肥用量对多穗型品种豫麦49-198和大穗型品种兰考矮早八根系生长分布和产量的影响.结果表明,2品种总根质量密度和各土层根质量密度变化趋于一致,呈先增加后减小的趋势,并于抽穗期达到最大.施氮量影响根质量密度的分布,2品种均以180 kg/hm2施氮处理根质量密度最大,其中豫麦49-198分别比360和0 kg/hm2处理增加12.59％和31.11％,兰考矮早八分别增加8.02％和15.79％.大穗型品种根质量密度与产量的相关性明显高于多穗型品种,表明通过氮肥用量调控根量对提高大穗型小麦产量的作用更大.

Effects of Nitrogen Application Rate on Root System Distribution and Grain Yield of Winter Wheat Cultivars

The effects of nitrogen application rate on root system distribution and grain yield of wheat cultivar Yumai 49-198 and Lankaoaizao 8 with two different spike shapes were studied under the condition of field with high soil fertility.The results indicated that,variation of the total root mass density and the root mass density in each depth soil layer exhibited the consistent tendency in two varieties and they reached a peak at the heading stage.There was a certain relationship between nitrogen application rate and the distribution of root mass density.The root mass density of the two cultivars under N 180 kg/hm2 treatment reached a maximum,compared with the N 360 kg/hm2 and N 0 kg/hm2 treatment,which increased by 12.59% and 31.11% for Yumai 49-198,and 8.02 % and 15.79% for Lankaoaizao 8,respectively.It was showed that the correlation between root system distribution and grain yield of the cultivar with large-size-spikes was more significant than that of the cultivar with multi-spike.The results indicated nitrogen application rate would be more instructive to regulate root development and to improve grain yield in wheat with large-size spikes than in wheat with multi-size spikes.